Draft control



Feb. 6, 1951 c. w. EAKIN 2,540,191

DRAFT coumor.

Filed July 15, 1949 2 Sheets-Sheet 2 Inventor Gar Z219 in AttorneyPatented Feb. 6, 1951 i 1 DRAFT CONTROL Curtis W. Eakin, Kennerdell, Pa.4 g I Application July 15, 1949, Serial No. 104,945

This invention relates to -a novel automatic damper for controlling thedraft from. a stove :or other heating or cooking unit and will auto-.matically restrict the outlet therethrough'to the chimney or stack asthe suction in the stack or chimney increases. 7 1

Another object of the invention is to provide a draft control ofextremely simple construction .and which may be manually adjusted torender it extremely sensitive to variations in the-suction in a chimneyor stack and which sensitivity of which will substantially eliminate theesca e of heat from a heating unit causing substantially all of the heattherefrom to be radiated into the enclosure to be heated thereby andwhich will react to even slight changes of the draft or suction in achimney or stack.

Still a further object of the invention is to provide a draft control orautomatic damper substantially all of the parts of which are enclosedyet which may be readily opened forinspection, adjustment or cleaningand which is provided with a minimum of moving parts.

Still another object of the invention is to pro} vide an automaticdamper or draft control hav- :ing braking means for checking themovement thereof to prevent a moving part thereof from striking thecontrol easingand'causing a noise or vibration to thereby provide a;control which will be noiseless and'which will cause no vibra- 'tion inoperation.

Various other objects and advantages of invention'will hereinafterbecome more fully apparent from the following description of thedrawings, illustratin presentlypreferred embodiments thereof, andwherein:

Figured is a side elevational view, partly in section, showing thedraftcontrol or automatic d'arnp'erfinterposed ina flue or chimney;Figure 2 is an enlarged longitudinal sectional view thereof takensubstantiallv along a plane as indicated by the line 22v of Figure 1;'

Figure 3 is a longitudinal vertical sectional view 01' the parts takenat a right angle to Figure'2. and substantially along a plane asindicated by the line 8-;3 of Figure 2; l

in d meme-sectional viewe'oithe p .,1 v z Claims. (01. 236. 45).

draft control: or. automatic damper taken sub.- stantially along planesas indicated by the lines 4 4 and 5- 5, respectively; of Figure 3, and

Figure-6 is a' fragmentary vertical sectional view showing a slightlymodified form of the invention. 1

Referring more specifically to the drawings, the automatic draft controlor damper constituting-the invention and'as illustrated in Figures ,1 to5, is designated generally and includesa housing designated generally 8,which is substantially rectangular in cross section; as best illustratedin Figures'4 and 5. The housing 8 is sub stantially wider in onedirection than in the other in cross section and the opposite wall portions 9 and I0 thereof which are spaced the greater distance apartareprovided with rounded inwardly curved complementary end'portions IIwhich merge with the more a'diacently disposed opposite side walls-l2-.an d I3; Extensions of said merging portions-Hand the side walls I2 and Iii-provide integral nipples-or sleeve portions 14 and I5 whichproject from the lower and upper ends, respectively, 'of the housing 8for receiving thereon sections [6 and ell-constituting adjacent ends ofsections of a flue or chimney for intere posing the housing 8 therein.The lower nipple constitutes the inlet endiof the automatic damper ordraft control-l and the uppernipple I5, the outlet end-thereofx L Thehousing *8 is provided with an internal shell l8'including, an uppera'rcuate portion l9 which extends generally toward the walls 9 and landwhich is upwardly bowed so as to be dis.- I

posed substantially": concentric. with the] upper wall portions 1 landbeneath'and spaced fror'nzthe outlet nipple 15:1; The innr fshell I 8also includes a dependingtwallflll; whichlfis spaced from and disposed'substantiallyiiparallel' to the wall 9 and the upper end of which".formsa continuationzof one end of the arcuate upper'shell portion I 9and the other end of which-terminates above and spaced from the 'l'owerinwardly bowed portion 1 l of said wall "9 to provide a passage entrance2! between the bottom portion of the housing'8 and the passageway 22defined by the wall '9 and "shell wall 20 and byw'one end of the arcuateshell portion!!! and th'e'upperinwardly bowed wall portion ll of thewall 9'; which passageway 22 extends from, the e'ntran'ce 2! thereof tothe outlet nipple 15, as bestillu'str ated in Figure 3. The arcuateshell portion f9, adjacent its opposite end, is; provided with asubstantially triangularshape ilocated djacent jhousinglwa ll it saidinner peningf 23, the widest-end oi which is :will hereinafter becomeapparent.

iiig the housing wall l3.

shell l8 including its portions 19 and 20, extends between the adjacentside walls l2 and [3, as clearly illustrated in Figures 4 and 5. Thehousing 8 is provided with an inverted L-shaped internally disposed wallmember 24 which extends between the adjacent walls i2 and I3 and whichhas its ends abutting against the wall ID, for a purpose which willhereinafter become apparent. The internalshell member 18 and theinternal wall member 24 may be secured in any suitable manner, notshown, within the housing 8.

The wall [2 is provided with a relatively large opening 25 constitutingan inspection and cleanout opening and which is normally closed b anexternally disposed cover plate 26 which is secured to the outer sideof'the wall I2 b screw fastenings 21. The wall [3 is provided with anopening 28 which is preferably externally flanged and the plate 26 isprovided with an opening 29 which aligns with the opening 28 and whichopenings are adapted to provid journals for a shaft 30 which isjournaled therein and which is fixed to or formed integral with theintermeposed within the housing .8 and which is of a width to extendsubstantially to the adjacent side walls 82 and I3 and of a length othat its upper end will travel along the under, concave side -diateportion of a damper vane 3i which is disofthe arcuate shell portion l9while its lower 7 end will be disposed for swinging movement adjacentthe inlet nipple i4 and from adjacent the center thereof toward thelower end of the shell wall 20, as seen in full and dotted lines,respectively, in Figure 3. A collar 32 is disposed on the shaft 30between one longitudinal edge of the vane 31 and the cover plate'26 forproperly spacing said edgeof the vane from the wall [2.

The lower portion of the damper vane 3| is provided with alongitudinally elongated openin'gor slot 33 for receiving a weightedelement 34 including a nut and bolt which is slidable in the opening 33longitudinally of the vane 3i and which is adapted to beitightened'forclamping said weighted element 34 in a plurality of adjusted positionsat different distances below'the shaft 30 for varying the effect of saidweight 34. A'segment-shaped housing 35 has an open side provided witha'fiange 36'which' is secured to ithe outer side 'of'the wan 43 b afastening 3"], which extends through the fiange'sfi, so that a "extendoutwardly through the lower, restrictedf .5 {portion of said housingside [3 constitutes the, other side wall of said segment-shaped housingportion of said segment -shaped housing 35, in

which said shaft 30 likewise journaled. A turning knob 33 is secured bya pin or fastening $9 'Ttothe'outer, exposedflend of the shaft30, cute'wardly of said housing 35 and'provides a means whereby the damper vane3| may be turned in either direction manually, for a purpose which Avane40 :istlisposed'for close fitting engagement within thehousing'35 andhas a hub'portion-H at its lower end which engages a portion of theshaftM'and which is secured thereto by a fastening A2 '56 that when theshaft-30 is turned in its journal openings 28 and 29,--the vane 40 willswing in the segment-shaped housing 35 and in close engagement with thewalls thereof,includ- The upwardly diverg- "ing walls 43 of said housing35 are provided with restricted openings-44 adjacent their uppersendsi.so that said" housing ands-itswahi 40 dashpot to restrict the turningmovement of the tion on the right-hand side of the damper vane 3| willpass upwardly through the opening 23 in the internal shell member I9 tothe outlet nipple [5 or around the right-hand end of the shell member19. The products of combustion entering the housing 8 on the left-handside of the {vane 31 will'pass upwardly through the passage 22,previousl described, into the outlet nipple l5. In the event that anexcess suction occurs in the flue above the housing 8, said suction willexert a pull on the ends of the vane 3| to cause it to swing clockwisewith its shaft 30 from its position of Figure 3 as seen in full lines'toits 'dotted line position of said figure. This will be partly caused bythe fact that some of the products of combustion will be trapped betweenthe shell wall 20 and the upper portion of-the vane 3| to exert apressure on said vane to swin it clockwise. The amount of pressurer'equird'to accomplish this swinging'movementiof the van'e 3| to itsdotted line position of Figure 3, will vary depending upon the locationof "the counterweight 34 which tends to retain the'vanein'lts full lineposition of Figure 3. As the vane '31 swings from its full line to itsdotted line position of Figure '3, its upper edge will pass across theopening 23 from the smaller end toward the larger end thereof and theproducts of combustion passing upwardly through said opening :23 to theright of the vane 3| will resist the clockwise swinging movement of thevane and thereby act as a brake to checkthe movement of the vane as itapproaches its dotted line position and to prevent the vane from bangingagainst the shell wall 20 and the upper corner of the internal wall 24.When the vane 3| is in its dotted line position of Figure 3, itslower-end is spaced from the lowerwall portion-ll of the wall 9-topermit a; limited amount of th products of combustion to pass throughthe entrance 2! into the passage 22 and some-products-rof combustion canass through the'opening 33 and thence to the opening'23, so that thedamper or vane 3| does not completely shutoff the flow of'the products:of combustion in any osition.- However. the products of combustion areprevented from escaping beyond the upper part of the vane 3l-due to thefact that the vane in it dotted line positionfengages the upper insidecorner 0; the-interior wail member 24 to thereby closethe upperright-hand side of the casing 8, as seen -in-Figure 3, -Wlien thesuction at the outlet nipple -|5 diminishes the weight 34 will returnthevane -3l"toward; full line or open position. *In additiohtmtheopening; 23 functioning to restrict. the swinging movement of the vanetoward its closed, dotted line position, thedashpot 35, .40 is provided--positi-vely preventing the vane 31 from-swinging; rapidly in eitherdirection to thereby prevent the vane from hanging against an internalparts of the housiing 8 to cause a noise or vibration. Thisis-accomplished due to the fact that the vane Mic! -the dashpot mustswing with-the vane 3i and in i asse sed.messen er ma netism.

ing "44 toward which it is moving and at the same time creates a suctionto draw" air into the dashpot housing through the other-opening 4*4,both' of which'openings are sufficiently small so that air will berestricted in its passage therethrough to thereby permit'the vane 40 toswing ;only; ata very slow speed. ,7 r

Obviously, the cover plate 26 can be removed for adjusting the weight 34andfor cleaning out the interior of the draft control housing 8. Scotmay also be removed from'the damper; vane 3| by "manually turning theknob 38,-with the vane 31 adjacent its dotted line position of Figure 3,

-'foi"bumping the ends of the vane against the in- -:ternal wallportions and 24 for knocking the soot from the vane,

With the weight 34 located adjacentjhe upper end of the Opening 33, thedamper vane 3| can be made sufliciently sensitive so that it will beclosed by an excessive heat entering the?; housing 8 through its inletl4 due to the fact that a suflicient amount of the products ofcombustion will then be trapped between the upper portion of the vane 3|and the internal wall 20 tofswing said vane clockwise and to its dotteduse position of Figure 3.

Figure 6 illustrates a slightly modified form of the invention andwherein the opening 33 and weight 34 are omitted and in lieu thereof anelongated threaded rod 45 is provided to retain the knob 38 secured tothe shaft in lieu of the fastening 39, said rod having oneend engaging athreaded opening 46 in the hub of the knob 38 and being advanced forclamping engagement with the shaft 30. The rod 45 is disposed in adepending position when the vane 3! is upright, so that said rod is inthe same plane asthe vane. A weight 41 is then threaded onto thelowerend of the rod 45 and may be adjusted toward and away from the knob 38for varying the extent that said weight will resist the closing movementof the vane 3|, in the same manner and'for the same purpose as theweight 34. v

Various other modifications and changes are contemplated and mayobviously be resorted to, without departing from the spirit or scope ofthe invention as hereinafter defined by the appended claims.

I claim as my invention:

1. A draft control comprising a housing having an inlet nipple at oneend thereof and an outlet nipple at its opposite end, said nipples beingadapted to be connected to adjacent ends of sections ,of a flue forinterposing the draft control therein, said housing constituting a partof the flue conduit, an internal sh disposed in said housing andprovided with a; arcuate end wall located adjacent the outlet n pie,said internal shellhaving a longitudinallyj. tending wall extending fromone end of said a uate wall portion and terminating adjacent the inletnipple and combining with a wall of said'hpusing to provide a restrictedpassage from adjacent: the inlet nipple to said outlet nipple, ashaftgxtending through andjournaled in said housingga damper vane fixedto said shaft and swing ably disposed in the housing and mounted formovement of either of its ends toward and away froms'aid longitudinallydisposed wall of said internal shell, one end of said damper-vane beingmovable across the concave, inner side of said arcuate wall of theinternal shell and the other er idthfereof being movab ,from an openposition adjacent the inlet nip and axially of the in to a positionagainst the adjacent and 0 said longitudinally by the housing will beclosed by the wane except"- for said limited entrance opening to thepassage; 2. A draftbontrol as in claim 1, said vane having-means fornormally maintaining it in a plane parallel to'the longitudinal axis ofthe housing and-of the adjacent flue sections, said vane being actuatedby suction in the outlet nipple of the housing for rocking the vane to aposition for substantially closing the passage through the housing.

3. A draft control as in claim 1, said vane having means for normallymaintaining it in a plane parallel to the longitudinal axis of thehousing and of the adjacent flue sections, said vane being actuated'by asuction in the outlet nipple of the housing for rocking the vane to aposition for substantially closing the passage through the housing, saidmeans comprising a weight mounted for vertical sliding movement on saiddamper vane toward and away from said shaft and having means forclamping it in a plurality of adjusted positions to the vane.

4. A draft control as in claim 1, said vane having means for normallymaintaining it in a plane parallel to the longitudinal axis of thehousing and of the adiacent flue sections, said vane being actuated by asuction in the outlet nipple of the housing for rocking the vane to aposition for substantially closing the passage through the housing, saidmeans comprising a threaded rod secured to and normally depending froman exposed end of said shaft and having a weight threaded thereon forvertical movement toward and away from the shaft, said threaded rodbeing disposed in the same vertical plane as the damper vane.

5. A draft control as in claim 1, said first mentioned arcuate portionof said internal shell having a tapered opening therein disposed nearthe end thereof remoteto the longitudinal wall of said shell, saidopening being tapered toward said longitudinal wall and forming anopening through the housing for the products of combustion, said firstmentioned end of the vane being movable across said opening as the vaneis moved to a closed position for closing the opening, and the enlargedend of said opening forming a brake means for checking the swingingmovement of the vane toward a closed position.

6. A draft control as in claim 1, a dashpot mounted on the outer side ofsaid housing through which an end of said shaft extends and in whichsaid shaft portion is journaled, said dashpot including a vane havingone end fixed to the shaft for checking the rotary movement of the shaftand swinging movement of the damper vane in either direction.

7. An automatic damper control comprising a housing having an inletnipple at one end thereof and an outlet nipple at its opposite end, saidnipples being adapted to be engaged by adjacent ends of adjacentsections of a, flue for interposing the housing in the flue, a shellsecured in said housing barring, a wall disposed longitudinally oi thehousing {and combining with portions 1 1 thezeof to form'ya restrictedpassage extending along: one," side of the housing from adjacent its:inlet-nippletoits outlet nipple, a vane swingably mounted in saidhousing, and a weight carried by said vane for normally holding thevanein a positionlongitudinally and centrally of the housing whereby theproducts of combustion can flow unimpeded through the, housing, saidshelihaving an arcuate end wall extending from one end ofthelongitudinal shell wall and disposed between the outlet nipple and theadjacent end 0! the. vane, said vane being adapted to be actuated by,suction-inthe outlet nipple of the housing for swinging said end of thevane to a position adjacent one end-of the areuate shell wall. to closevone part of the-housing and to position the other Nu x nher 1 -Name V.1, 492,083-s q Mortonr Jan;.3,-1922- 1512;687- schme1z, Feb; 9; 19281,602,989 Montgomery Oct. 12,1926

.2;12,3 01 4 Breese' Mar. 28,1939

